Simulated evolution of the highest peak amplitude I_max with respect to a full precession period with phase ϕ ∈ [0,2 π]. The geometrical parameters are shown in the titles. The two fitting models are shown, Gaussian in red and Lorentzian in blue. Both fits overlap almost perfectly. The highest intensity does not depend on the fitting profile, as expected. The intensity contrast can reach 10 for panel a) and be rather weak for other configurations, such as panel c), which shows a variation of only 5%.